aio_mlock • man page

aio_mlock - asynchronous

aio_mlock • man page

aio_mlock - asynchronous

aio_mlock (2)

Leading comments

Copyright (c) 2013 Gleb Smirnoff <glebius@FreeBSD.org>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
doc...

(The comments found at the beginning of the groff file "man2/aio_mlock.2freebsd".)

NAME

LIBRARY

Lb libc

SYNOPSIS

In aio.h
Ft int
Fn aio_mlock struct aiocb *iocb

DESCRIPTION

The
Fn aio_mlock
system call allows the calling process to lock into memory the
physical pages associated with the virtual address range starting at
Fa iocb->aio_buf
for
Fa iocb->aio_nbytes
bytes.
The call returns immediately after the locking request has
been enqueued; the operation may or may not have completed at the time
the call returns.

The
Fa iocb
pointer may be subsequently used as an argument to
Fn aio_return
and
Fn aio_error
in order to determine return or error status for the enqueued operation
while it is in progress.

If the request could not be enqueued (generally due to
aio(4)
limits),
then the call returns without having enqueued the request.

The
Fa iocb->aio_sigevent
structure can be used to request notification of the operation's
completion as described in
aio(4).

RESTRICTIONS

The Asynchronous I/O Control Block structure pointed to by
Fa iocb
and the buffer that the
Fa iocb->aio_buf
member of that structure references must remain valid until the
operation has completed.

The asynchronous I/O control buffer
Fa iocb
should be zeroed before the
Fn aio_mlock
call to avoid passing bogus context information to the kernel.

Modifications of the Asynchronous I/O Control Block structure or the
memory mapping described by the virtual address range are not allowed
while the request is queued.

RETURN VALUES

Rv -std aio_mlock

ERRORS

The
Fn aio_mlock
system call will fail if:

Bq Er EAGAIN

The request was not queued because of system resource limitations.

Bq Er EINVAL

The asynchronous notification method in
Fa iocb->aio_sigevent.sigev_notify
is invalid or not supported.

If the request is successfully enqueued, but subsequently cancelled
or an error occurs, the value returned by the
Fn aio_return
system call is per the
mlock(2)
system call, and the value returned by the
Fn aio_error
system call is one of the error returns from the
mlock(2)
system call, or
Er ECANCELED
if the request was explicitly cancelled via a call to
Fn aio_cancel .